Premium
Color vision model of macLeod and Boynton
Author(s) -
Fry Glenn A.
Publication year - 1989
Publication title -
color research and application
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.393
H-Index - 62
eISSN - 1520-6378
pISSN - 0361-2317
DOI - 10.1002/col.5080140309
Subject(s) - chromaticity , luminance , diagram , optics , constant (computer programming) , color vision , physics , mathematics , computer science , statistics , programming language
MacLeod and Boynton started off with the assumption that the fundamental blue falls on the x' axis of Judd's 1951 chromaticity diagram. This leads to a constant luminance diagram in which the lines that converge at the fundamental blue in Judd's diagram are parallel. MacLeod and Boynton tried to solve this problem by a slight change in one of the constants in the transformation equations. It turns out that what this does is to shift the position of the alychne on Judd's diagram so that it does not coincide with the x' axis. The blue fundamental no longer lies on the alychne. This makes it possible to derive a constant luminance chromaticity diagram in which the fundamental blue falls at one of the corners. After having created this new diagram, they used it to formulate a theory of color vision in which the blue cones contribute nothing to luminance. This procedure needs to be understood because it can be used to convert any theory of color vision in which all three cones contribute to luminance to one in which only two contribute to luminance. This has nothing to do with having the blue fundamental fall on the x' axis. A more serious problem is that Judd has made an error in his assessment of the luminosity coefficients and the concepts of MacLeod and Boynton need to be reformulated in terms of the CIE 1931 chromaticity diagram.